Modern flight deck displays for vehicles (such as aircraft or spacecraft) display a considerable amount of information, such as vehicle position, speed, altitude, attitude, navigation, target, and terrain information. In the case of an aircraft, most modern displays additionally display a flight plan from different views, either a lateral view, a vertical view, or a perspective view, which can be displayed individually or simultaneously on the same display.
The lateral view, generally known as a lateral map display, is basically a top-view of the flight plan, and may include, for example, a top-view aircraft symbol, waypoint symbols, line segments that interconnect the waypoint symbols, and range rings. The lateral map may also include various map features including, for example, weather information, terrain information, political boundaries, and navigation aids. The terrain information may include situational awareness (SA) terrain, as well as terrain cautions and warnings which, among other things, may indicate terrain that may obstruct the current flight path of the aircraft. The perspective view provides a three-dimensional view of the vehicle flight plan and may include one or more of the above-mentioned features that are displayed on the lateral map, including the terrain information. In this regard, some modern flight deck display systems incorporate a synthetic terrain display, which generally represents a virtual or computer simulated view of terrain rendered in a conformal manner.
The primary perspective view used in existing synthetic vision systems emulates a forward-looking cockpit viewpoint. Such a view is intuitive and provides helpful visual information to the pilot and crew, especially during airport approaches. In this regard, synthetic display systems for aircraft are beginning to employ realistic simulations of airports that include details such as runways, taxiways, ground markings, buildings, etc. Although such a high level of detail is valuable and desirable when the aircraft is very close to the airport, it may not be necessary at other phases of the flight. For example, if the aircraft is more than a mile away from the airport, then the pilot and crew might only need to know the general location of the airport or the specific destination runway. Displaying additional features (such as other runways, ground markings, or landscape features) may be unnecessary and distracting. The display of such additional features can result in a cluttered and user-unfriendly synthetic flight display.